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| Oxygen Consumption and Ammonia Excretion in Jellyfish Rhopilema esculenta with Various Sizes under Different Illumination and Temperature |
| SONG Jing,LI Xiao-dong,WU Yin,LIU Xu |
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Abstract Oxygen consumption and ammonia excretion were determined by the Winkler method and the Nessler's reagent method in juvenile jellyfish Rhopilema esculenta with various sizes under different ambient illumination, pH 7.9～8.1 and salinity of 25.1. The relationship between dry weight(m)and the bell diameter(D)was found to be represented as the equation:m=0.0003 D~2-0.0007 D+0.0427, r~2=0.9913. There was a negative regression function among oxygen consumption rate(OCR), ammonia excretion rate(AER)and the bell diameter(D):OCR=0.0063 D~2-0.3531 D+6.1533, r~2=0.9751; AER=0.4221 D~2-26.585 D+518.83, r~2= 0.9587. The juvenile jellyfish had significantly greater OCR and AER under light than under darkness(P＜0.01). The OCR and AER showed a tendency to increase with the increase in water temperature. The significant increases in AER was only found in 30 ℃ group and other three groups(P＜0.01)and the significant increases in OCR were observed in the high water temperature groups except from the 20 ℃ group and the 25 ℃ group(P＜0.05). The asphyxia was found at the dissolved oxygen concentration of 0.45 mg/L for the juvenile jellyfish with bell diameter of 15 mm under light than under darkness.
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Received: 25 March 2010
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